Question: Multiply.
Answer: $27 \times 7$ and $0.27 \times 0.7$ multiply the same digits in the same order. So, the product of both problems will also have the same digits in the same order. Let's multiply $27 \times 7$. Then we can estimate to place the decimal point in the product of $0.27 \times 0.7$. $\begin{aligned} 27&\\ \underline{ \times 7}&\\ 49}\\ \underline{+140}}\\ 189 \end{aligned}$ Let's estimate to place the decimal in $0.27 \times 0.7$. $\begin{aligned} 0.27 \times 0.7 &\approx 0.3 \times 0.7\\\\ &\approx \dfrac{3}{10}\times \dfrac{7}{10}\\\\ &\approx \dfrac{21}{100}\\\\ &\approx 0.21 \end{aligned}$ Where can we place the decimal in $189$ to get a product close to $0.21$ ? $0.189 = 0.27 \times 0.7$